Steel TIPS

03.1998 > Compatibility of Mixed Weld Material

By Alvaro L. Collin and James P. Putkey

Compatibility of Mixed Weld Material

For many years fabricators and erectors have
used, as common practice, electrodes with
different specifications and classifications in the
same weld (mixed weld metals). Mixed weld
metal results from:
Different root pass and fill-in pass
electrodes.
Weld repair work to both shop and field
welds.
The more recent practice of making field
welds over shop welds.
Compatibility is a basic requirement of mixed weld metals. The different
electrodes and the mixed weld metal must have, as a minimum, matching yield
strength, tensile strength, and impact properties--if impact properties are
specified.
In this SteelTIPS, the authors will limit their discussion to two welding processes:
Shielded Metal Arc Welding (SMAW).
Flux Cored Arc Welding (FCAW).